The Chainsaw is a portable mechanized saw commonly used as a tool for cutting down trees. Due to its intimidating noise and potential for mutilation, it is frequently employed as a weapon in pop culture, including in horror movies such as The Texas Chainsaw Massacre, violent crime films such as Scarface, and videogames such as Doom, Gears of War, and the Resident Evil game series.
In Grand Theft Auto: Vice City, Grand Theft Auto: San Andreas, Grand Theft Auto: Liberty City Stories, Grand Theft Auto: Vice City Stories and Grand Theft Auto: Chinatown Wars the player can acquire a chainsaw to use as a weapon. Standing still while pressing the attack button will allow the player to swipe with the chainsaw; pressing the button while moving does not allow swiping, but allows the player full mobility. The chainsaw is the only melee weapon which slows the player to a walking pace; in GTA San Andreas, the player also cannot jump with the chainsaw equipped. As such, it is unsuitable for attacking fleeing targets. In GTA Vice City, drops of blood can be seen spattered at the screen when the player successfully attacks a target.

Use of a chainsaw in public will cause pedestrians to panic, and, if a police officer is nearby, the player will gain a one-star Wanted level, regardless of whether the player harms anyone in the process.

The chainsaw can easily remove parts such as hoods, bumpers and even doors from vehicles, however its blows glance off vehicles' main chassis, thus causing only superficial damage.

In Grand Theft Auto: Vice City, tapping the attack button will make Tommy rev thechainsaw, and frighten nearby pedestrians. This can be done both while moving and standing. It can only be done while moving in Grand Theft Auto: San Andreas.

In Grand Theft Auto: Chinatown Wars you can hijack cars in front of police by using the chainsaw on the car. When the passengers walk out, take the car without any worry of alerting the police. However, be careful of accidentally killing the escaping passengers.